
Existing studies reveal that elite and popular preferences influence U.S. Supreme Court decision-making. However, scholars remain uncertain about the specific conditions under which this influence occurs. This gap questions how external factors constrain an institution often seen as insulated.
The author argues that constraints on the Court stem from justices' fear of nonimplementation, especially in cases where their rulings lack clear enforcement mechanisms. This explains why implementation power differs significantly between types of cases:
Analysis shows the Court's implementation power is greater in vertical cases. Conversely, constraint and responsiveness to external preferences are strongest in important lateral cases (e.g., those requiring cooperation from nonjudicial actors).
The research demonstrates that Supreme Court constraints aren't uniform but depend on the justices' institutional anxieties about enforcement failure, revealing a more complex dynamic between courts and society.

| The Semi-Constrained Court: Public Opinion, the Separation of Powers, and the U.S. Supreme Court's Fear of Nonimplementation was authored by Matthew E. K. Hall. It was published by Wiley in AJPS in 2014. |